1. Field of the Invention
This invention relates to deflection compensating press rolls of the type having a stationary bearer and a roll shell for rotation thereabout. The shell is supported on a number of hydrostatic support elements disposed in a row. The support elements are subdivided into predetermined numbers of groups to which hydrostatic pressure fluid is fed at different pressures through ducts in the bearer.
2. Description of the Prior Art
Deflection compensating rolls have been used to apply pressure to webs of material, such as paper. For example, Swiss Pat. No. 514,088, or the corresponding U.S. Pat. No. 3,802,044 to Spillmann et al. discloses a roll having bores in the bearer thereof associated with the individual hydrostatic support elements, and pressure fluid is supplied to these elements through the bores.
To produce a relatively large number of bores in the bearer, or beam, is a relatively expensive process. In addition, an excessive number of bores in the bearer greatly weakens the bearer. Also, when the support elements are combined into groups to which the pressure fluid is fed at given pressure through a common bore in each case, it is extrememly difficult or impossible to change the groups. I have invented a deflection compensating press roll in which the ducts can be provided at relatively low cost while avoiding the disadvantages of the prior art and reducing substantially the stresses on the bearer. My invention also provides efficient means for replacement and rearrangement of the groups of ducts of the bearer.